This disclosure relates to a panel module and a display device.
In recent years, display devices with a transparent front panel on the front of the display module have been increasing; the transparent front panel can be an input interface component like a touch panel or a component for enhancing the appearance or protecting the surface of the display screen. One of the simple structures for such display devices is a structure (air-gap bonding structure) such that the display module and the front panel are bonded along the periphery with a double-sided tape (refer to JP 2015-141374 A, for example).
A touch panel module, which is an example of the front panel, generally has a structure such that a cover panel and a sensor glass are bonded together substantially over the entire face with a transparent optical elastic resin layer. The refractive index of the sensor glass is approximate to the refractive index of the optical elastic resin layer. This bonding technology using an optical elastic resin layer is called optical bonding (OB); it has not only the optical effects but also mechanical effects such as providing shatter protection in case of breakage of the front panel and increasing the impact resistance.
To form an optical elastic resin layer, optical clear resin (OCR) or optical clear adhesive (OCA) can be employed. The OCR is a liquid resin that cures with UV light or heat and the OCA is a sheet-type baseless adhesive tape.
JP 2015-141374 A discloses a reinforced structure of a display device including a touch panel. This display device includes a plurality of straight double-sided tapes (for example, polyolefin-based ones) that are bonded to a housing of a liquid crystal display (LCD) module along its rectangular opening with gaps therebetween and a plate-shaped member attached to cover the opening. The plate-shaped member includes a protection plate on the front and a touch panel bonded to the protection plate with an optical elastic resin layer.
The display device further includes a resin applied to the housing to fill the gaps between double-sided tapes and be in contact with the plate-shaped member. The touch panel is fixed to the housing along its periphery by the double-sided tapes and the resin. The resin in the gaps between double-sided tapes is in contact with the end faces of the touch panel and the protection plate. The resin shows reinforcement effects against the force to detach the optical elastic resin layer between the protection plate and the touch panel.